NOVEL STRUCTURES FOR CARBON NANOTUBE FIELD EFFECT TRANSISTORS

2009 ◽  
Vol 23 (19) ◽  
pp. 3871-3880 ◽  
Author(s):  
RAHIM FAEZ ◽  
SEYED EBRAHIM HOSSEINI

A carbon nanotube field effect transistor (CNTFET) has been studied based on the Schrödinger–Poisson formalism. To improve the saturation range in the output characteristics, new structures for CNTFETs are proposed. These structures are simulated and compared with the conventional structure. Simulations show that these structures have a wider output saturation range. With this, larger drain-source voltage (Vds) can be used, which results in higher output power. In the digital circuits, higher Vds increases noise immunity.

2019 ◽  
Vol 14 (11) ◽  
pp. 1512-1522 ◽  
Author(s):  
Seyedehsomayeh Hatefinasab

Scaling down the size of transistor in the nanoscale reduces the power supply voltage, as a result, the design of high-performance nano-circuit at low voltage has been considered. Most of digital circuits are composed of different components which determine the performance of the entire digital circuits. With the improvement of these components, the digital circuits can be optimized. One of these components is full adder for which various structures have been proposed to improve its performance, among them the two novel full adder structures are based on Gate-Diffusion Input (GDI) structure and half-classical XOR/XNOR logic (SEMI XOR/XNOR) modules. In this paper, Carbon Nanotube Field Effect Transistor (CNTFET)-based low power full adders by using SEMI XOR logic style and GDI structure are presented. Due to the incomparable thermal and mechanical properties of the CNTFET, it can be the first alternative to substitute the metal oxide field effect transistors (MOSFET). The digital circuits have the better performance based on CNTFET. Therefore, the three proposed full adders in this paper are designed based on CNTFET technology with many merits, such as low power dissipation, less energy delay product (EDP), and high speed at various supply voltages, frequencies, temperatures, load capacitors, and the number of tubes. Moreover, these proposed full adders occupy the minimum area consumption and have better performance in comparison with previous standard full adders. All simulations are done by using the Synopsys HSPICE simulator in 32 nm-CNTFET technology and layout of all full adder circuits are presented on Electric.


2007 ◽  
Vol 121-123 ◽  
pp. 503-506
Author(s):  
D.L. Pulfrey

An assessment is made of the suitability of the carbon nanotube field-effect transistor for applications in nanoelectronics.


2021 ◽  
Author(s):  
Sweta Chander ◽  
Sanjeet Kumar Sinha ◽  
Prince Kumar Singh ◽  
Ashish Kumar Singh

Abstract This paper presents a numerically simulated Ge-source based Tunnel Field Effect Transistor with (TFETs) SiO 2 segregation between the channel and drain. The developed device has been compared with conventional TFET and without isolated heterojunction TFET. The use of oxide segregation between channel and drain enhances the performance of the device in terms of ON-state current as well as subthreshold swing (SS). The electrical characteristics such as surface potential, electric field, transfer characteristics, output characteristics of the proposed device have been studied. The temperature variation of the proposed device has also been studied. The proposed device offers high ON current of 3x10 4 A, I ON /I OFF ratio of ~10 11, and enhanced SS of 30 mV/dec. The validity of the proposed device has been done by Synopsys Sentaurus TCAD.


2012 ◽  
Vol 1416 ◽  
Author(s):  
Woo Jae Park ◽  
Sung-Jae Chung ◽  
Man S. Kim ◽  
Steingrimur Stefansson ◽  
Saeyoung Ahn

ABSTRACTEnzyme-Linked Immuno-Sorbent Assay (ELISA), and other methods based on the same principle, are sensitive and specific, but they suffer from several disadvantages, such as their inherent complexity and requirement for multiple reagents, incubation and washing steps and require a relatively large sample size. We have adapted a new carbon nanotube field effect transistors (CNT-FET) based platform to capture Escherichia coli antigens using only the capture anti-body showing good correlation with an established ELISA assay contrived positive and negative specimens were used to test the new CNT-FET platform and results were obtained within three minutes per each sample. The test is easy to perform, rapid, and cost efficient making it a valuable screening tool for E. coli. In this study, we looked at the applicability of using CNT field effect transistor based biosensor as a rapid diagnostic platform for Escherichia coli O157:H7. The CNT-FETs platform detected positive E. coli samples in three minutes using only 2.5 μL of sample volume. This low sample volume required by the CNT-FET platform can be especially advantageous for diagnostic tests constricted by limited amount of samples.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 995
Author(s):  
Xuesong Yao ◽  
Yalei Zhang ◽  
Wanlin Jin ◽  
Youfan Hu ◽  
Yue Cui

Chemical and biological sensors have attracted great interest due to their importance in applications of healthcare, food quality monitoring, environmental monitoring, etc. Carbon nanotube (CNT)-based field-effect transistors (FETs) are novel sensing device configurations and are very promising for their potential to drive many technological advancements in this field due to the extraordinary electrical properties of CNTs. This review focuses on the implementation of CNT-based FETs (CNTFETs) in chemical and biological sensors. It begins with the introduction of properties, and surface functionalization of CNTs for sensing. Then, configurations and sensing mechanisms for CNT FETs are introduced. Next, recent progresses of CNTFET-based chemical sensors, and biological sensors are summarized. Finally, we end the review with an overview about the current application status and the remaining challenges for the CNTFET-based chemical and biological sensors.


2001 ◽  
Vol 706 ◽  
Author(s):  
Marcus Freitag ◽  
A. T. Johnson

AbstractWe use scanning gate microscopy to precisely locate the gating response in single-wall nanotube devices. Junctions of metallic and semiconducting nanotubes show a dramatic increase in transport current when they are electrostatically doped with holes at the junction. We ascribe this behavior to the turn-on of a reverse biased Schottky barrier. A similar effect is seen in field-effect transistors made from an individual semiconducting single-wall carbon nanotube. In this case, there are two Schottky barriers at the metal contacts, one of which is forward, and one of which is reverse biased. The gating action is only observed at the reverse biased Schottky barrier at the positive electrode. By positioning the gate near one of the contacts, we convert the nanotube field-effect transistor into a rectifying nanotube diode. These experiments both clarify the gating mechanism for nanotube devices and indicate a strategy for diode fabrication based on controlled placement of acceptor impurities at a nanotube field-effect transistor.


Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 164
Author(s):  
Ke Han ◽  
Shanglin Long ◽  
Zhongliang Deng ◽  
Yannan Zhang ◽  
Jiawei Li

This paper presents a germanium-around-source gate-all-around tunnelling field-effect transistor (GAS GAA TFET). The electrical characteristics of the device were studied and compared with those of silicon gate-all-around and germanium-based-source gate-all-around tunnel field-effect transistors. Furthermore, the electrical characteristics were optimised using Synopsys Sentaurus technology computer-aided design (TCAD). The GAS GAA TFET contains a combination of around-source germanium and silicon, which have different bandgaps. With an increase in the gate-source voltage, band-to-band tunnelling (BTBT) in silicon rapidly approached saturation since germanium has a higher BTBT probability than silicon. At this moment, germanium could still supply current increment, resulting in a steady and steep average subthreshold swing ( S S AVG ) and a higher ON-state current. The GAS GAA TFET was optimised through work function and drain overlapping engineering. The optimised GAS GAA TFET exhibited a high ON-state current ( I ON ) (11.9 μ A), a low OFF-state current ( I OFF ) ( 2.85 × 10 − 9 μ A), and a low and steady S S AVG (57.29 mV/decade), with the OFF-state current increasing by 10 7 times. The GAS GAA TFET has high potential for use in low-power applications.


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